FIG. 2.

Result of follow-up of patients with biochemical remission according to the sTg2 value. In total, 10 patients (1.3%) showed clinical evidence of disease during the follow-up. Of the 750 patients who had sTg2<1 ng/mL, 5 (5/750, 0.7%) showed a clinical recurrence. Of the 37 patients with sTg2≥1 ng/mL, clinical recurrence was detected in 5 patients (5/37, 13.5%). There were no recurred patients with positive TgAb2. sTg2 and TgAb2, Tg and TgAb measured 1–3 years after sTg1 (stimulated Tg measured 12 months after ablation) during thyroid hormone withdrawal; NCED, no clincial evidence of disease (based on physical examination, neck ultrasonography, and any other imaging performed as part of the clinical evaluation, performed at the end of follow-up, regardless of the level of Tg); clinical recurrence/persistence, reappearance of pathologically proven malignant tissue or metastatic lesion such as lung, bone, and brain metastasis.